A harem-inspired Moorish fantasy design in a Victorian-era Welsh castle.

Hidden beneath the famous St. Peter's Basilica is a veritable city of the dead that may hold the remains of St. Peter himself.

A marvel of Byzantine engineering under the streets of Istanbul.

Where commuters walk through remnants of an ancient Greek necropolis.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

The most famous location in China was home to whole dynasties worth of imperial rulers.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

What looks like a suicide in progress is actually a statue of Sigmund Freud.

Not quite the menace it once was, this monster still has some chops.

An ancient Scottish rock formation said to be the gravesite of a giant remains ensconced in legend and intrigue.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

Fortune tellers, snake charmers, poets, and storytellers all gather on this historic square in Morocco.

An ancient capital city that dates back 3,000 years old and harbors many surprises.

A "miracle" that seems to produce more holy fistfights than holy revelations.

Two stone columns flank the grand Venice square, but there were supposed to be three.

This strange bovine gargoyle is said to have been put in as a passive aggressive form of revenge.

Home of the unusual art of water puppetry, one of Vietnam's oldest curiosities.

The headquarters of the Mahanikai school of Buddhism, Thailand's largest monastic order.

A mechanical clock built in 1914, with a rotation of 12 historical figures on its face.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

The iconic boulevard is the perfect place to catch sight of a bicycling skeleton, a levitating Satan, or a chef with his head stuck in a pizza.

One of Amsterdam's narrowest houses is located right across the canal from its widest.

The indecision over what to place in this square was immortalized with a plaque.

Climb to the top of its spiral spire for spectacular views of Copenhagen.